Internal-combustion engine



June 3 1924.

H. SCHNEIDER INTERNAL COMBUSTION ENGINE Filed Sept. 26, 1922 2 Sheets-Sheet 1 June 3 292% H. SCHNEIDER INTERNAL COMBUSTION ENGINE 2 Shets-Sheet 2 Filed Sept. 25, 1922 Patented June 3, i924.

UNHT

HEINRICH SCHNEIDER, or ILLNAU, SWITZERLAND.

I TERNAL-coMBUsTIo E GINE.

Application filed September 26, 1922. Serial No. 590,658.

To all whom it'ma concern:

Be it known that I, HEINRICH SCHNEIDER, a citizen of the Republic of Switzerland, residing at Illnau, Canton Zurich, Switzen land, have invented a certain new and useful Improvement in Internal Combustion Engines, of which the following is a specification, reference being had therein to the accompanying drawing.

The present invention relates to improvements in internal combustion engines having exhaust ports arranged at the end of the stroke.

\Vith combustion engines of this type scavenging offers considerable ditficulties, es pecially with quick running two stroke cycle engines, in which the time available for scavenging is very short and considerable scavenging pressures have to be employed. lVith known engines of this type the ports for admitting air for scavenging are arranged at the end of the stroke, inconsequence thereof the scavenging agent has to be forced during the short scavenging time in the upward direction towards the compression space and has to flow back again. A portion of the scavenging agent escapes directly through the exhaust ports which are arranged diametrically opposite to the inlet ports and the combustion gases are whirled, the scavenging is incomplete and a scavenging pump of large outputs is required.

In case scavenging valves are provided in the cover of the cylinder whirls are also caused in the combustion gases whereby the output. of the. engine is considerably decreased.

The above. mentioned disadvantages are overcome by the combustion engine forming the subject matter of the present invention. According to the latter the combustion engine is provided with a compression space arranged in the cylinder head, the'compression space being provided with a constricted portion, onto which a gradual enlargement to the diameter of the cylinder joins, further a centrally arranged member adapted to admit air for scavenging purposes and an annular chamber for .said air arranged in the cylinder head and surrounding said member being provided, whereby the scavenging air enters from the annular chamber into the compression chamber, flows through the constricted portion of the latter in a closed stream which extends tothe space of the cylinder and like a piston forces the exhaust gases out of the compression space and of the interior of the cylinder through the ex haust ports.

The compression space may be designed as a chamber confined by surfaces of rotation, the walls of the portion of the compression space in the cylinder head being formed by such surfaces and the part projecting into the compression chamber and a sleeve valve is preferably employed for admitting the scavenging air.

Another feature of the invention consists in the provision of means adapted to impart a rotating flow to the scavenging air and to the charge mixture respectively.

Constructional examples of the internal combustion engine according to the invention are illustrated on the accompanying drawings, in which:

Fig. 1 is a vertical section through the upper part of a two stroke cycle internal combustion engine with direct injection of the fuel,

Fig. 2 shows a modified constructional example of the engine shown in Fig. 1.

Figs. 3 and t illustrate further constructional examples of internal combustion engines according to the invention.

Fig. 5 is a section along line XIIIXIII of Fig. 1;

Referring now to Fig. 1, 1 designates the engine cylinder, 2 is the piston and 3 are the exhaust ports uniformly distributed around the circumference of the cylinder at the end of the stroke. lVithin the cylinder head 4 a compression space 5 is arranged confined by surfaces of rotation, which space is provided with a constrictedportion 6. A gradual enlargement onto the cross-sectional area of the cylinder joins to the compression space 5. For the purpose of imparting a rotating flow to the scavenging air and to the charge mixture, ribs 7 arranged at an angle with the axis of the cylinder are provided inside the compression space 5 and the piston head is provided with bores 8 the direction of which is at an angle to the axis of the cylinder. In the upper part of the compression space the member for admitting the scavenging air, i. e, an annular slide valve 10 is arranged resting in its closed position on a seat 11, the part 12 projecting into the compression space being arranged inside the annular slide valve 10. A fuel nozzle 13 is centrally mounted in the part 12, the fuel being supplied to the nozzle 13 by means of the fuel pipe 14.

The part 12 which is water cooled is fixed to the cylinder head 4: by means of the cap member 15, the latter, the part 12 and the slide valve 10 forming together an upper chamber 20 and a' lower chamber 21, into which chambers pressure oil is alternately admitted and led ofi whereby the raising and lowering movements of the annular slide valve 10 are controlled. The spring 22 serves to ensure the closing movement of the slide valve 10. \r

In the cylinder head 4: chambers 25 and 26 in which cooling water circulates, and an annular chamber 27 for taking up the air for scavenging and for the charge mixture respectively are provided, the chamber 27 surrounding the annular slide valve 10. The air for scavenging flows through the channels 28 into the compression space when the annular slide valve is in its open position. The latter is provided with piston rings 30 for packing the valve against the part 12 and the cylinder head at. In its open position the slide valve 10 is cooled on its inner and outer surfaces and over its whole length, the scavenging air cools the valve seat 11 on flowing into the compression space. The valve 10 is so arranged that it is not in touch with the direct products of combustion.

The operation of the above described internal combustion engine is as follows:

Iowards the end of the expansion stroke,

the exhaust ports 3 are uncovered by the piston and after the expansion has taken place the valve 10 is opened and air for scavenging flows from the annular chamber 27 into the compression space, which air forces the combustion gases in front .of it. a rotating flow being imparted to the air by the ribs 7, whereby the current of scavenging air extends to fill the space of the cylinder after it has flowed past the restricted port-ion of the compression space and like a piston forces the combustion gases out of the compression space andthe cylinder and through the exhaust ports. By suitably choosing the moment of closing of the slide valve 10 any desired degree of admission and excessive admission respectively maybe obtained. During the compression stroke the whole content of the cylinder is forced into the compression space, whereby the ribs 7 impart again a rotating flow to the charge mixture which rotation is further increased during the last portion of the compression stroke by means of the bores 8.

The combustion chamber having walls formed by surfaces of rotation the rotating flow imparted to the scavenging air and to' the charge mixture respectively continues undisturbed.

When the fuel is injected into the rotating air a very quick combustion takes place at which the greatest portion of the air takes part, "during the ex ansion a further rotating flow is imparte to the combusting mixture by the ribs 7, whereby a complete mixing and a complete combustion is caused during the first stage of the expansion stroke. In this manner the difficulties and defects which are inherent to known internal combustion engines with regard to the mixture, to the flame velocity and to the after-burning of the charge are overcome. a The indicator diagram gets broader at the top and more like the diagram of a Diesel-engine. The combustion occurs quickly and at a high temperature so that the thermal efliciency as well as the specific output are materially increased in consequence of the effective mixture.

The shape of the compression space as well as the arrangement of the central member for admitting scavenging air and of the annular chamber for said air render it possible to attain a perfect scavenging.

The constructional example illustrated in Fig. 2 shows the following modifications in comparison to the constructional example shown in Fig. 1.

A ring shaped rib 31 projects into the annular chamber 27 containing the scavenging air so that the air flows through the annular space between the rib 31 and the annular slide valve 10. The latter is provided with ribs 32 in order to effect a good transmission of the heat resulting from the previous combustion to the scavenging air. The ring shaped rib 31 conducts the current of the air towards the ribs 32 of the slide valve. The diameter of. the valve seat 11 is so dimensioned that with the valve closed the internal pressureurges the valve towards its seat. i

The annular slide valve 10 is actuated from the cam shaft 33 bymeans of cams 34, 35 and a bell crank lever 37 provided with rollers and pivoted on the pin 36. A

counter-"lever 38 co-acting with a spring 39. is pivoted on the lever 37. A stirrup 41 the of the fuel bymeans of compressed air. The

fuel nozzle is arranged nearer to the piston when the latter is in its highest position,

than in the arrangement shown in F 9 and the end of the piston is concaved. Im mediately below the seat 11 oft-he annular slide valve 10 designed in the same manner as in Fig. 2 the compression space widens out to the diameter of the cylinder.

\Vith the constructional example according to Fig. 4 double piston valves 48 and 49 are provided for the admittance of the air for scavenging, which piston valves are actuated by eccentric-rods 50 and 51.

In order to further utilize and increase the rotating movement of the air with the engine illustrated in Fig. 1 the inlet channels for the air as well as the exhaust ports may be provided with bridge-parts 52 shaped like guide blades of a turbine as is shown in Fig. 5. The rotating flow generated in theports is of particular importance with engines having pistons working in opposite directions.

Instead of the members for admitting scavenging air illustrated, valves of any other suitable type suchas single or double valves, cylindrical or conical valves shaped to suit the compression space may be utilized and the actuation ofthe members may be carried out in any suitable manner.

I claim:

1. An internal combustion engine comprising a piston, a cylinder having exhaust ports near the end of the expansion stroke of the piston, a cylinder head. a compression chamber arranged in said cylinder head and having a constricted portion an axially arranged member adapted to admit air for scavenging purposes. and a gradually en- .larged portion between the compression space and the cylinder.

2. An internal combustion engine comprising a piston, a cylinder having exhaust ports near the end of the expansion stroke of the piston, a cylinder head, a compression chamber in said cylinder head and having a constricted portion, the .walls of said compression space being shaped as surfaces of rotation, an axially arranged member adapted to admit air for scavenging purposes, an annular chamber for the scavenging air provided in said cylinder head and surrounding said member, and a gradually enlarged portion between the compression chamber and the cylinder.

3. An internal combustion engine, com-' prising a, piston, a "cylinder having exhaust ports near the end of the expansion stroke of the piston, a cylinder head, a compression chamber in the latter having a constricted portion, the walls of said compression space being shaped as surfaces of rotation. air

axially arranged member adapted to admit air .for scavenging purposes, an annular chamber for the scavenging air provided in said cylinder head and surrounding said member, a gradually enlarged portion beadapted to admit air for scavenging purtween the com ression chamber and the cylinder, and a fiiel injection nozzle arranged in the axis of the cylinder.

4. An internal combustion engine comprising a piston, a cylinder having exhaust ports near the end of the expansion stroke of the piston, a cylinder head, a compression chamber in said cylinder head and having a constricted portion, the walls of said compression chamber being shaped assurfaces of rotation, an axially arranged member adapted to admit air for scavenging purposes, an annular chamber for the scavenging air provided in said cylinder head and surrounding said member, a gradually enlarged portion between the compression chamber and the cylinder, a fuel injection nozzle arranged in the axis of the cylinder, and means adapted to impart a rotating flow to the scavenging air and to the air of the charge.

5. An internal combustion engine comprising a piston, a cylinder having exhaust ports near the end of the expansion stroke of the piston, a cylinder head. a compression chamber in said cylinder head and having a constricted portion, the walls ofsaid com pression chamber being shaped as surfaces of rotation, an axially arranged sleeve valve poses, an annular chamber for the scavenging air provided in said cylinder and surrounding said valve, a gradually enlarged portion between the compression chamber and the cylinder, a fuelinjection nozzle arranged inthe axis of the cylinder, and ribgr provided in the compression chamber arranged at. an angle to the axis of the cylinder and adapted to imparta rotating'flow to the scavenging air and to the air of the charge. 1

6. An internal combustion engine comprising a piston, a cylinder havingexhaust ports near the end of the expansion stroke of the piston, a cylinder head, a compression chamber in said cylinder head and having a constricted portion, the walls oi said compression space being shaped as surfaces of rotation, an annular slide valve co-axially arranged to the cylinder and adapted to admit air for scavenging purposes, an annular chamber for the scavenging air provided in said cylinder head and surrounding said valve. and a gradually enlarged portion between the compression chamber and the cylinder. I

7. An internal combustion engine com prising a piston having exhaust ports near the end of the expansion stroke of the piston,

the scavenging air provided in said cylinder head and surrounding said valve, a gradually enlarged portion between the compression space and the cylinder, lugs on said 5 annular valve, a stirrup shaped member engaging said lugs, a lever mechanism-carrying said stirrup shaped member and provided with rollers, and a cam-shaft having cams co -operating with said rollers for actuating said lever mechanism and thereby said annular slide valve.

In testimony whereof I aflix my signature.

HEINRICH SCHNEIDER. 

